Infineon ICE2QR1765Z 20W5V离线开关电源解决方案

2011年11月07日 10:35 发布者：1046235000

Infineon公司的ICE2QR1765Z是CoolSET®-Q1系列器件,是准谐振的功率集成电路,采用BiCMOS技术,集成了带起动单元的650V CoolMOS,能工作在非常低的负载,突发模式的待机功耗小于0.1W,内置了数字软起动,主要用在LCD监视器, DVD R/W, DVD,蓝光DVD,机顶盒等.本文介绍了ICE2QR1765Z产品亮点和主要特性, 方框图和典型应用电路以及20W/5V评估板主要指标,电路图, 变压器结构图和材料清单,PCB布局图.

The CoolSET®-Q1 series (ICE2QRxx65Z) is the first generation of quasi-resonant integrated power ICs. It is optimized for off-line switch mode power supply applications such as LCD monitor, DVD R/W, DVD Combo, Blue-ray DVD, set top box, etc. Operating the MOSFET switch in quasi-resonant mode, lower EMI, higher efficiency and lower voltage stress on secondary diodes are expected for the SMPS. Based on the BiCMOS technology, the CoolSET®-Q1 series has a wide operation range (up to 25V) of IC power supply and lower power consumption. It also offers many advantages such as quasi-resonant operation till very low load which increases the average system efficiency,

Active Burst Mode operation which enables an ultra-low power consumption at standby mode with small and controllable output voltage ripple, etc.

ICE2QR1765Z产品亮点:

• Quasi resonant operation

• Active Burst Mode to reach the lowest standby power requirement <100mW@no load

• Digital frequency reduction for better overall system efficiency

• Integrated 650V avalanche rugged CoolMOS® with startup cell

• Pb-free lead plating; RoHS compliant

ICE2QR1765Z主要特性:

• 650V avalanche rugged CoolMOS® with built-in startup cell

• Quasi resonant operation till very low load

• Active burst mode operation for low standby input power (< 0.1W)

• Digital frequency reduction with decreasing load for reduced switching loss

• Built-in digital soft-start

• Foldback point correction and cycle-by-cycle peak current limitation

• Maximum on/off time limitation

• Auto restart mode for VCC Overvoltage and Undervoltage protections

• Auto restart mode for overload protection

• Auto restart mode for overtemperature protection

• Latch-off mode for adjustable output overvoltage protection and transformer short-winding protection

图1. ICE2QR1765Z方框图

图2. 20W5V EVAL-ICE2QR1765Z评估板框图

20W5V Evaluation Board with Quasi-Resonant CoolSET® ICE2QR1765Z

This application note is a description of 12W switching mode power supply evaluation board designed in a quasi resonant flyback converter topology using ICE2QR1765Z Quasi-resonant CoolSET®.The target application of ICE2QR1765Z are for set-top box, portable game controller, DVD player, netbook adapter and auxiliary power supply for LCD TV, etc. With the CoolMOS® integrated in this IC, it greatly simplifies the design and layout of the PCB. Due to valley switching, the turn on voltage is reduced and this offers higher conversion efficiency comparing to hard-switching flyback converter. With the DCM mode control, the reverse recovery problem of secondary rectify diode is relieved. And for its natural frequency jittering with line voltage, the EMI performance is better. Infineon’s digital frequency reduction technology enables a quasi-resonant operation till very low load. As a result, the system efficiency, over the entire load range, is significantly improved compared to conventional free running quasi resonant converter implemented with only maximum switching frequency limitation at light load. In addition, numerous adjustable protection functions have been implemented in ICE2QR1765Z to protect the system and customize the IC for the chosen application. In case of failure modes, like open control-loop/over load, output overvoltage, and transformer short winding, the device switches into Auto Restart Mode or Latch-off Mode. By means of the cycle-by-cycle peak current limitation plus foldback point correction, the dimension of the transformer and current rating of the secondary diode can both be optimized.Thus, a cost effective solution can be easily achieved.